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  • 28 December 2011 Volume 20 Issue 4
      
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  • Research of Peak Efficiency Influencing Factor Corresponding with Density During Analysis of Dry Biological Sample by Using γ-spectrometry
    ZHANG Jing, XU Cui-hua, LI Wen-hong, ZHAO Li, TUO Fei
    2011, 20(4): 385-386. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.038
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    Objective To study the influencing factor of peak efficiency during analysis of dry powder biological samples by using gamma spectrometry. Methods Measurement of radionuclides were carried out with GC3018 low background high purity germanium (HPGe) γ spectrometer. LabSOCS software was used for simulation after validated by calibration source. Results Peak efficiency of low-background HPGe γ spectrometer decreased exponentially with the increased density of sample box and sample material. Conclusions Based on fitting functions, a correction factor of efficiency for different mass of samples can be obtained quickly. It can meet the need for rapid determination of γ-emitting radionuclides in biological samples during nuclear emergency.
  • The Investigation of Activity Concentrations of Radionuclides in Foods in the Adjoining Areas of Haiyang Nuclear Power Plant
    XU Jia-ang, LI Quan-tai, CHEN Ying-min, LI Hai-liang, BI Ming-wei
    2011, 20(4): 387-389. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.003
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    Objective The datas of the activity concentrations of the critical nuclides in foods of the adjoining areas of Haiyang Nuclear Power Plant were abtained before the operation,and the main goal of the investigation was to determine the background levels of the radionuclides distinguishing from those in the normal operation, nuclear accident and after the accident for evaluating or interpreting the radioactive impact to the foods. Methods The samples of the wheats,cabbages, fishes and milk of the adjoining areas of Haiyang Nuclear Power Plant were collected. The methods about preprocessing and preparation of the samples were based on Technical Criteria for Radiation Environmental Monitoring (HJ/T61-2001). The activity concentrations of the critical nuclides in foods were tested using HPGe-γ Energy Spectrum Measurement Systerm. Results The results showed that the average levels of 226Ra,232Th,137Cs and 40K in wheats were 7.4×10-2 Bq·kg-1,1.8×10-1 Bq ·kg-1,5.5×10-2 Bq·kg-1 and 8.2×101 Bq·kg-1 respectively, their range were from 2.7×10-2 Bq·kg-1 to 2.1×10-1 Bq·kg-1, from 1.1×10-1 Bq·kg-1 to 3.0×10-1 Bq·kg-1,from 1.9×10-2 Bq·kg-1 to 1.0×10-1 Bq·kg-1 and from 3.5×101 Bq·kg-1 to 1.2×102 Bq·kg-1 respectively. The average levels of 226Ra,137Cs and 40K in cabbages were 1.8×10-2 Bq·kg-1, 1.8×10-2 Bq·kg-1 and 5.0×101Bq·kg-1 respectively, their range were from 1.3×10-3 Bq·kg-1 to 2.7×10-2 Bq·kg-1, from 1.1×10-2 Bq·kg-1 to 3.3×10-2 Bq·kg-1 and from 4.0×101 Bq·kg-1 to 8.6×101 Bq· kg-1 respectively. The average levels of 226Ra,137Cs and 40K in fishes were 3.7×10-2 Bq·kg-1, 1.4×10-2 Bq·kg-1 and 2.1×101 Bq·kg-1 respectively. The average levels of 226Ra,137Cs and 40K in the milk was 1.2×10-2 Bq·kg-1, 1.8×10-2 Bq·kg-1 and 3.8×101 Bq·kg-1 respectively. The activity concentrations of the other radionuclides in foods were lower than the levels of the Minimum Detectable Activity Concentration respectively. Conclusions The activity concentrations of the artificial and natural radionuclides in foods of the adjoining areas within 30 km of Haiyang Nuclear Power Plant are about to the background levels. The committed equivalent doses of the residents suffered from the critical nuclides in foods are in the background levels.
  • The MCNP simulation of the X-ray leakage of X-ray security inspection Equipment
    WANG Kai, LIU Bin, HU Wen-chao, ZHAO Wei
    2011, 20(4): 390-393. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.039
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    Objective To simulate the radiation leakage of the X-ray security inspection equipment used in the subways stations. Methods We use the MCNP4C code to simulate the X-ray leakage of the equipment during the working process. Result the biggest amount of radiation received by the body is 8.26μSv/a, however, if the Lead screens of the X-ray security equipment is intact, the amount of radiation received by the body is only 0.0727μSv/a. The final. Conclusions When the baggage get in/out the X-ray security inspection equipment, the gas in Lead screens was made, and then the amount of radiation received by human body increased; The amount of radiation received by the body is close to but still below 10μSv/a which is the exemption criteria set by the "safety of radiation sources of ionizing radiation protection and basic standards"(GB18871-2002).
  • Effects on Translocation and Activation of Cerebellar Protein Kinase C in Rabbit by Microwave Irradiation
    LIU Yong, HUANG Wei-chu, LIU Da-xing, CHENG Xu-hao
    2011, 20(4): 394-395. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.072
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    Objective To investigate the effects of microwave irradiation on translocation and activation of protein kinase C(PKC) in rabbit cerebellum. Methods Thirty rabbits were divided randomly into control and microwave irradiation group(including 0 hour, 3 hours, 12 hours, 24 hours and 72 hours subgroups after irradiation), rabbits of microwave irradiation group were exposed to 90 mW/cm2 Sfrequency range microwave irradiation for 30 minutes, rectal temperature were detected immediately after irradiation and specific absorption rate(SAR) value were calculated, PKC activity of cerebellar neuron endochylema and cytolemma were detected with improved TaKai method. Results Rectal temperature of rabbits increased 2.41℃ after irradiation, and SAR value was 4.65 Kcal/kg. PKC activity of cerebellar neuron endochylema have no significant change, but PKC activity of cerebellar neuron cytolemma decreased significantly after irradiation. Conclusion After 90 mW/cm2 microwave irradiation for 30 min, heating effect was produced in the rabbit bidy, and the capability of cerebellar PKC translocation and activation decreased significantly.
  • Study of a 3D GIS for Management of Electromagnetism Environment
    WANG Dong, LUO Qi-xiu
    2011, 20(4): 396-398. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.011
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    Objective To develope a 3D electromagnetism environment GIS for meeting the needs of cities,especially in built-up areas. Methods Technology of Electromagnetic spectrum analysis,2D/3D seamless integration and database technology are adopted in the system to achieve the integrated management of electromagnetic environment and geographic datas. Results The system can realize quantitative management of the spatial information,the properties of electromagnetic radiation facilities and 3D frequency spectrum analysis of electromagnetic environment. Conclusion The system can provide scientific support for electromagnetic radiation environmental protection,improve the scientific decision-making and macro-control level of government departments,further establish and improve a efficient regulatory system of electromagnetic environment.
  • The Therapeutic Effect Of Three-dimensional Conformal Radiation Therapy Combined with Conventional Radiotherapy for Nasopharyngeal Carcinoma
    LIANG Feng, LV Zhong-hong, YAO Zhi-jun, CAO Yong-zhen
    2011, 20(4): 399-401. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.066
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    Objective To observe the therapeutic effect of three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC). Methods 78patients with NPC was treated by radiation schedule in two phases. In the first phase, nasopharyngeal lesions and metastases of all patients were treated by three-dimensional conformal radiation therapy (3DCRT) with a fraction of 2-5Gy daily, 5 day per weeks, total dose 30Gy. The second phase T1N0 or parts of T2N0 patients were done by Conventional radiotherapy with total dose 55Gy on two small lateral opposing fields + with total dose 50Gy on neck on tangential field, adding a 3cm block. Patients with lymph node metastasis were given 55Gy on the dacio-neck field (After 40Gy, two small lateral opposing fields were used to boost the primary tumor while the spinal cord shielded) + with total dose 55Gy on lower neck on tangential field. The upper bound of designed therapeutic field was set to connect with lower bound of main therapeutic field. Results Three months after treatment,the rate of CR、PR、SD、PD were 38.5%、55.1%、5.1%、1.3%, Total effective rate(CR + PR) were 93.6%. The 1-year、2-year、3-year and 5-year local-regional control rates were 92.3%、88.5%、78.2%、70.5%. The 1-year、2-year、3-year and 5-year overall survival rate were 96.2%、89.7%、83.3%、71.8%. Appearing early radiation response is well tolerated and no obviously mouth difficulties and cranial nerve damage observed. Conclusion Clinical result of early-course three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC) is good.
  • The Anti-Oxygen Effect of Sodium Borocaptate on Radiation Mice
    QIAN Tian-tian, HE Ying, WANG Qing-rong, CHEN Wei, Shen Xian-rong
    2011, 20(4): 402-403. https://doi.org/10.13491/j.cnki.issn.1004-714x.2011.04.074
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    Objective To investigate the anti-oxygen effect of sodium borocaptate on radiation mice. Methods 42 BALB/c mice was randomly divided into negative control group, model control group, positive control group(WR2721,200 mg/kg), 20 mg/kg BSH group, 40 mg/kg BSH group, and 80 mg/kg BSH group. The preparations were administrated in peritoneal injection with 0.2 ml/20g. Negative control group and model control group were administrated with normal saline. Positive control group was administrated twice before irradiation. Irradiated mice were irradiated by γ-ray of 60Co (0.8 Gy/min) with the dose of 6 Gy. In 14 days after being irradiated, SOD and MDA were detected. Results Comparing with model control group, SOD in peripheral blood was increased significantly in the 20 mg/kg. d BSH group, 40 mg/kg. d BSH group and 80 mg/kg. d BSH group(P < 0.05). Comparing with the model control group, MDA was decreased significantly in the BSH treated groups (the 20 mg/kg. d group P < 0.05, the 40 mg/kg group and the 80 mg/kg group P < 0.01). Conclusion BSH has the effects of increasing the activity of SOD and decreasing the concentration of MDA on mice. The results suggest that BSH has the anti-oxygen activity and it should be one of the mechanisms of BSH on radioprotection.